Add more flint metrics

[noCharger]

Description

Metrics included in this PR:

request.metadata.read.2xx.count
request.metadata.read.4xx.count
request.metadata.read.5xx.count
request.metadata.read.403.count

request.metadata.write.2xx.count
request.metadata.write.4xx.count
request.metadata.write.5xx.count
request.metadata.write.403.count

request.metadata.heartbeat.failed.count

result.metadata.write.2xx.count
result.metadata.write.4xx.count
result.metadata.write.5xx.count
result.metadata.write.403.count

"streaming.running.count";
"streaming.failed.count";
"streaming.success.count";
"streaming.heartbeat.failed.count";

1. Revised jobType values; allow default values when not defined.
2. Changed all "running" metrics from counter to gauge, as the counter only reports delta.
3. Refactored methods for metrics recording logic
4. Added metrics on request/result metadata and streaming.

Issues Resolved

#117

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[penghuo]

result.metadata.write.2xx.count
result.metadata.write.4xx.count
result.metadata.write.5xx.count
result.metadata.write.403.count

does InstanceRole required?

[noCharger]

result.metadata.write.2xx.count
result.metadata.write.4xx.count
result.metadata.write.5xx.count
result.metadata.write.403.count

does InstanceRole required?

There are no dimensions by default. Users can configure dimensions for their own purposes with #238. If we want to drop dimensions on a group of metrics, we need to support metric groups and group policy concepts, which are up for discussion.